JPS6362886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a resin molded coil, and particularly to a method for manufacturing a resin molded coil without using a casting mold.

FIG. 1 is a partial side sectional view of a coil showing a conventional method of manufacturing a resin molded coil. In FIG. 1, first, a coil 2 is formed by alternately winding a base material and a conductor around a winding core 1. Next, a terminal 4 having a screw hole 401 is attached to the terminal board 3 made of a glass epoxy resin laminate, and after connecting the lead 5, which is the end of the coil 2, to this terminal 4, a filler material 6 is placed around the lead 5. The outer insulating layer 7 is formed by wrapping a nonwoven fabric made of, for example, polyethylene terephthalate several times, and wrapping a nonwoven fabric with poor permeability, such as an aromatic polyamide nonwoven fabric, at least once over the outer insulating layer 7. The coil is wound to form an outermost insulating layer 8, and the end of the winding is sealed to form a sealed portion 9 to form an elementary coil 10. Next, the bare coil 10 is impregnated with a thermosetting resin including a photocurable resin, and the circumferential surface of the coil is irradiated with ultraviolet rays to form a film to prevent leakage, and then this is heated and cured, and then slowly cooled. Remove the winding core 1, drill a through hole in the outer insulating layer 7 and the outermost insulating layer 8 to reach the screw hole 401 of the terminal 4, and attach a terminal screw (not shown) and a decorative nut (not shown). to complete manufacturing.

However, in the resin molded coil manufactured by the above-mentioned conventional method, the seal portion 9 remains as a step on a part of the outer periphery of the coil, which impairs the aesthetic appearance and reduces the product value compared to a coil manufactured using a mold. make low. In addition, the outer circumferential insulating layer 7 and the outermost insulating layer 8 are evenly wound around the circumferential surface of the coil and can be wound tightly, but at the top of the terminal board 3, tension is applied to the terminal board corners 301 and In this case, the outer peripheral insulating layer 7 and the outermost peripheral insulating layer 8 are in a floating state, and a gap 11 is created. Therefore,
When impregnating the bare coil 10 with resin, the resin enters the gap 11 and becomes a clear resin layer after the manufacturing is completed, causing residual cracks. Furthermore, the clear resin layer formed by resin entering the outer peripheral insulating layer 7, the outermost peripheral insulating layer 8, and the gap 11 on the terminal board 3 will crack when drilling a through hole in the upper part of the terminal 4 with a drill or the like. tend to occur,
Cracks may also occur when attaching a cosmetic nut (not shown). Furthermore, screw hole 4
There was a drawback that it was difficult to position the through hole coaxially with 01.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a partial side sectional view of a coil showing an embodiment of the method for manufacturing a resin molded coil according to the present invention. In the figure, the same parts as in FIG. 1 are given the same reference numerals. In FIG. 2, a coil 2 is formed by alternately winding a base material and a conductor around a winding core 1. Next, the terminals 4 having screw holes 401 are attached to the terminal board 3 made of a glass epoxy resin laminate, and the mold release treatment portions 12 are formed on the upper surfaces of the terminal board 3 and the terminals 4. The mold release treatment section 12 is formed by applying, for example, a silicone-based grease-like mold release agent, and any other mold release agent having heat resistance exceeding 130° C. may be used. Next, after connecting the lead 5 to the terminal 4, filler material 6 is packed around the lead 5 without any gaps, and a nonwoven fabric made of, for example, polyethylene terephthalate is wound several times to form the outer insulating layer 7. Non-woven fabric with poor permeability from above,
For example, after wrapping an aromatic polyamide nonwoven fabric or the like at least once to form the outermost insulating layer 8, the end of the winding is positioned near the center of the terminal board 3, and the end of the winding is sealed to form the seal portion 9. , one of the end faces of the coil is sealed to form an elementary coil 10. Next, the bare coil 10 is held upright with the unsealed end of the coil facing up, and after being impregnated with a thermosetting resin including a photocurable resin, the circumferential surface of the coil is irradiated with ultraviolet rays to form a coating. After applying leak-proofing treatment by forming, it is placed in a drying oven and cured by heating, but before it is completely cured, when it is about 70% to 80% cured, use a knife etc. to cut the corner 3 of the terminal board.
The outer insulating layer 7 and the outermost insulating layer 8 on the terminal board 3 are scraped off until the terminal board 3 is visible on the entire periphery, that is, at an angle of 45 degrees on all four sides of the rectangle. Remove terminal board 3
The outer surface of the resin is exposed and the resin is then completely heated and cured. After this heating and curing, it is slowly cooled and the winding core 1 is removed to complete the production of the resin molded coil.

The properties of general thermosetting resins are that even if the resin has completed polymerization and is 100% cured,
If it is kept at a high temperature, it becomes flexible and can be easily cut with a knife. In particular, it has been found through experiments that the cutting operation at the point of 70% to 80% hardening, as in the above example, is the easiest to cut.

Note that descriptions of the method of attaching the terminals 4 to the terminal board 3, the method of connecting the terminal board 3 and the leads 5, and processes such as finishing and painting after release are omitted because they are not the gist of the present invention.

This invention has been made as described above, and by exposing the terminal board 3 to the coil surface, cracks caused by the clear resin layer between the outer peripheral insulating layer 7 and the outermost peripheral insulating layer 8 on the terminal board 3 can be prevented. There is no need to worry about this, the reliability of product characteristics is improved, and the work of drilling terminal holes and positioning work is omitted, reducing work time. In addition, by positioning the seal portion 9, which is the end of the winding of the outermost insulating layer 8, on the terminal plate 3 and finally removing the seal portion 9, the outer curved portion of the coil has a smooth and seamless surface. can be obtained, and the aesthetic appearance can be improved.

As described above, the present invention has various effects such as no occurrence of cracks, improved reliability, reduced working time, and improved appearance.

[Brief explanation of drawings]

FIG. 1 is a partial side sectional view of a coil showing a conventional method for manufacturing a resin molded coil, and FIG. 2 is a partial side sectional view of a coil showing an embodiment of the method for manufacturing a resin molded coil according to the present invention. In the figure, 1 is a winding core, 2 is a coil, 3 is a terminal board, 301 is a terminal board corner, 4 is a terminal, 5 is a lead, 6 is a filler material, 7 is an outer peripheral insulating layer, 8 is an outermost peripheral insulating layer, 9 10 is a sealing portion, 10 is an elementary coil, and 12 is a mold release treatment portion. Note that the same parts in each figure are given the same reference numerals.

Claims (1)

[Claims] 1. A first method for creating a coil by winding a conductor around a winding frame.
a second step of applying a mold release agent to the outer surface of the terminal board to be connected to the coil, and applying an outer peripheral insulating layer and an outermost peripheral insulating layer around the coil and the terminal board to form a bare coil. a third step in which the winding end portion of the outermost insulating layer is the upper part of the terminal board; and a third step in which the coil is impregnated with a resin and heated and cured, and the outer periphery on the terminal board is heated and cured during heat curing. A method for manufacturing a resin molded coil, comprising a fourth step of removing an insulating layer and the outermost insulating layer to expose the outer surface of the terminal board. 2 The removal of the outer peripheral insulating layer and the outermost peripheral insulating layer is performed when the resin is cured by 70% to 80%.
2. Method for manufacturing a resin molded coil as described in Section 1.